1. Field of the Invention
The present invention is directed to a power generating assembly structured to be capable of dual functionality by the inclusion, in a common housing, of an engine assembly which may be connected in operative relation to a power take-off, and a compressor assembly interactive with the engine assembly and structured to further pressurize fluid flow therethrough concurrently to the operation of the engine assembly.
2. Description of the Related Art
Currently space conditioning assemblies which include both heating and cooling systems are commonly operated by means of an electric motor serving as the source of power. However, recent developments in the design and structure of both heating and cooling systems have led to an increased interest in engine driving systems. The primary difference being that the electric motor is replaced as a primary power source by a fuel powered engine. Such an alternative means of power has distinct advantages relating to variable speed operation capabilities, higher overall efficiency, efficient high temperature waste heat recovery, etc. Further, and by way of example only, the efficient waste heat recovery can be utilized for domestic water heating, process heating, steam generation, etc. thereby reducing the overall operating cost of the entire system. Accordingly, research in this area has led to the determination that engine driving conditioning assemblies, including both heating and cooling systems, can lead to the development of a system having improved cost and performance and an expanded range of products. Further, much of the research and development efforts currently being conducted are focused on developing small, engine driving systems that are suitable for single family dwellings as well as small commercial applications.
In general terms, engine driving cooling systems employ a conventional vapor compression cycle. The main components of such a compression system are the compressor, condenser, expansion valve and evaporator. In operation, the main steps of the conventional vapor condenser cycle include the compressor raising the pressure of low pressure refrigerant to a higher pressure level resulting in the higher pressure refrigerant having a higher saturation temperature. The condenser removes the heat from the high pressure vapor, allowing it to condensed to liquid at the higher temperature. As a result, heat is rejected to the cooling water. The expansion valve reduces the pressure of the liquid refrigerant and because the pressure is reduced, the saturation temperature is reduced as well. At this point some liquid may flash to vapor during the process. The evaporator supplies heat to the refrigerant from the chilled water. This heat boils the refrigerant at the lower temperature and pressure. By removing heat from the chilled water stream the chilledwater is cooled. Chillers are used to cool a chilled water stream which is then sent to the individual air coils. The air coils in turn cool the air being delivered to an intended space or zone. It is further acknowledged that smaller units, such as split systems and packaged roof top units, typically do not employ chilled water streams or cooling water streams, but rather use air coils to both directly remove heat from the condenser and cool and de-humidify the conditioned air stream with the evaporator. evaporator supplies heat to the refrigerant from the chilled water. This heat boils the refrigerant at the lower temperature and pressure. By removing heat from the chill water stream the chill water is cooled. Chillers are used to cool a chill water stream which is then sent to the individual air coils. The air coils in turn cool the air being delivered to an intended space or zone. It is further acknowledged that smaller units, such as split systems and packaged roof top units, typically do not employ chill water streams or cooling water streams, but rather use air coils to both directly remove heat from the condenser and cool and de-humidify the conditioned air stream with the evaporator.
In determining the most effective type of gas engine to be used as the primary power source in space conditioning systems, a variety of different internal combustion engines have been considered. In the conventional gasoline powered internal combustion engine, the combustion of fuel takes place in a confined space or cylinder and produces expanding gases that are used to provide the mechanical power. The most common internal combustion engine is the four stroke reciprocating engine used in the vast majority, if not almost all gasoline powered automobiles or vehicles. In such an application, mechanical power is supplied by a piston moving within the cylinder. Reciprocating movements of the piston within the cylinder serves to rotate or drive a crankshaft which is connected, by gearing to the drive wheels of the vehicle. An ignition spark is provided by an electrical system associated with the vehicle deriving power from a battery.
The diesel engine is also used to power vehicles, particularly trucks or other vehicles intended for heavy load conditions, but is also used as the basic power plant for a number of other commercial or industrial applications. The diesel engine is heavier and generally considered to be more powerful than the gasoline engine and burns a fuel less volatile than gasoline. The diesel engine differs from the gasoline engine in that the ignition of fuel is caused by the compression of air in its cylinder in the presence of a certain amount of heat, instead of a spark generated within a combustion cylinder. Typically the speed and power of the diesel engine are controlled by varying the amount of fuel injected into the cylinder. As set forth, diesel engines are widely used to power industrial and relatively small electric generators, continuously operating pumps as well as ships, trucks, locomotives and some automobiles.
One of many internal combustion engines capable of operating on either gasoline or diesel fuel is the free-piston engine, which was designed and developed in France in the early 1950""s. Typically, the free-piston engine is a two cycle engine having a minimal amount of working parts and, as set forth above, is capable of operating on both diesel and gasoline fuel. When utilized as an engine/generator the free-piston engine comprises one moving part which may generally be defined by two spaced apart pistons interconnected to one another by a connecting rod having its opposite ends secured to each of the two pistons. The piston rod assembly is xe2x80x9cfree floatingxe2x80x9d or free moving. Further, the engine may be adjusted to assume any compression ratio needed to operate, using a variety of different fuels and combustion processes to facilitate low fuel consumption, when properly regulated by computer control. Recognized advantages of the free-piston engine over the four cycle gasoline engine, of the type generally described above, is the elimination of the crank shaft, thereby reducing weight and inertia factors in the operation of the engine. In addition, there is a greatly reduced number of moving parts, which significantly reduces the requirements for bearings and further at least partially eliminates frictional movements between moving parts. In addition, the utilization of a complicated valve train and timing functions associated with a four cycle engine is eliminated. Finally, there is no xe2x80x9cwastedxe2x80x9d strokes typically employed in the operation of a conventional four cycle engine.
While it is apparent that extended research and development has been conducted in the areas briefly discussed above, there is a still a need for a more versatile power generating assembly which is designed and structured to incorporate many of the advantage of the above noted devices. Such an improved power generating assembly should be capable of dual functionality in terms of generating power to any one of a plurality of different power take-off devices as well as provide a compressor function in the pressurization of fluid or more specifically refrigerant vapor, which may used in a variety of different heating or cooling systems.
The present invention is directed to a power generating assembly structured to concurrently perform dual functions. More specifically, the power generating assembly of the present invention incorporates both an engine assembly and a compressor assembly in a common housing. The engine assembly and the compressor assembly are partially segregated but yet interactive with one another during the operation of the power generating assembly. The interactive relation between the compressor assembly and the engine assembly is accomplished through the cooperative workings of a piston assembly comprising at least one but preferably two free moving pistons which are an operative, working component of both the engine assembly and compressor assembly. In addition, the design and structure of the piston assembly is such as to substantially isolate the respective paths of working-fluid flow through of the compressor assembly and engine assembly. Accordingly, this interactive yet at least partially segregated working relation between the compressor assembly and engine assembly allows each to perform working functions which are not necessarily related to one another in terms of work output.
Therefore, the engine assembly may be operatively or drivingly connected to a power take-off, such as but not limited, to an expansion gas turbine. The power take-off, regardless of its structural embodiment, can be used to perform various different categories of work, which may or may not be related to the work or operative functioning of the compressor assembly. The compressor assembly may be incorporated into a space conditioning system or cooling system and more specifically serves to increase the pressure of a refrigerant vapor for subsequent transfer, after pressurization, to a condenser or other component associated with the space conditioning assembly.
In at least one preferred embodiment, to be described in greater detail hereinafter, the power generating assembly is designed and structured to operate on natural gas fuel. Naturally the power generating assembly of the present invention is capable, with little or no modification, of operating using a variety of combustible fuels or fuel mixtures. Accordingly, the fuel enters the housing, which is structured to enclose and movably support both the engine assembly and the compressor assembly, in direct reactive relation to the aforementioned piston assembly. The housing includes at least one cylinder which is structured to not only receive the fuel entering the housing but facilitate compression thereof by the aforementioned one or more pistons, as they concurrently travel into a compression phase associated with the engine assembly. The ignition of the fuel will cause forced travel of the pistons into an expansion phase of the engine assembly. Importantly, the structure and disposition of the piston assembly is such as to define a compression phase of the compressor assembly concurrently to an expansion phase of the engine assembly. Therefore, during continuous operation of the power generating assembly of the present invention, cyclical movement of the piston assembly, defines a sequence of alternate compression and expansion phases of both the engine assembly and the compressor assembly. The alternate compression and expansion phases of the engine assembly and compressor assembly are, as generally described above, more specifically intended to concurrently define a compression phase of the engine assembly while at the same time defining an expansion phase of the compressor assembly. The normal cyclical movement of the piston assembly will then alternatively and concurrently define an expansion phase of the engine assembly, while at the same time defining a compression phase of the compressor assembly.
Forced cyclical movement of the piston assembly in the manner described above is accomplished by the expansion or ignition of the fuel within the receiving chamber. In addition, biasing means in the form of a variety of different spring structures or other force generating mechanisms may be directly connected to or alternatively otherwise act on each of the one or more pistons of the piston assembly in a manner which forces the piston assembly between the aforementioned alternate compression and expansion phases of the engine assembly and the compressor assembly. Accordingly, the biasing means may be defined, in at least one embodiment of the present invention, by one or more spring mechanisms or structures disposed and structured to exert a biasing force on each of the one or more pistons as set forth above. Alternatively and also by way of example only, the biasing means can comprise a significantly different or structurally distinguishable mechanism such as, but not limited to a fluid cushion chamber.
Regardless of the specific structural embodiments incorporated within the power generating assembly of the present invention, it is structured to operate on a dual functionality basis thereby increasing its efficiency and significantly reducing its cost of operation while enhancing its overall versatility in terms of being adaptable for a variety of different practical applications.